8ms Timer for serial port access
From: Jens Schumacher (jens.schumacher_at_uni.de)
Date: 10/28/03
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Date: Tue, 28 Oct 2003 12:09:34 -0500
Hello,
I need to collect data from the serial port every 8ms since the device
connected to the port works at 120Hz. This doesn't seems to work properly
due to the 10ms time slice interval of a normal i386 kernel. The
communication to the serial port is done in user space at the moment and is
not loaded as a module. I read a lot in the history of the newsgroup and
there are some solutions recommended. From low latency kernel patches to the
use of real-time Linux. But I'm pretty new to Linux and feel not comfortable
by patching the kernel since I don't know how a low latency path affects
other programs on the system.
It is important that I get the data nearly every 8 ms because I don't want
the serial port buffer to overflow and loose data. But the use of real-time
Linux seems to be a overhead to me.
What about soft-real-time? I looked at the sched* functions, but could'nt
get it running as fast as I want.
What about using the rtc?
Is it also possible to run the application at that frequency to work with
the data I get?
Thank you very much,
Jens Schumacher
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